Attention!
NCOMMAS
works with versions of DART before Manhattan (9.x.x) and has yet to be updated. If you are interested in
using NCOMMAS
with more recent versions of DART, contact DAReS staff to assess the feasibility of an update.
Until that time, you should consider this documentation as out-of-date.
dart_to_ncommas
is the program that updates a ncommas netCDF-format restart file (usually
ncommas_restart.nc
) with the state information contained in a DART output/restart file (e.g.
perfect_ics, filter_ics, ...
). Only the CURRENT values in the ncommas restart file will be updated. The DART
model time is compared to the time in the ncommas restart file. If the last time in the restart file does not match
the DART model time, the program issues an error message and aborts.dart_to_ncommas
will be used on DART files that have a header
containing one time stamp followed by the model state.dart_to_ncommas
to read the assim_model_state_ic
files that have two
timestamps in the header. These files are temporarily generated when DART is used to advance the model. One timestamp
is the 'advance_to' time, the other is the 'valid_time' of the model state. In this case, a namelist for ncommas
(called ncommas_in.DART
) is written that contains the &time_manager_nml
settings appropriate to advance
ncommas to the time requested by DART. The repository version of the advance_model.csh
script has a section to
ensure the proper DART namelist settings for this case.dart_to_ncommas
:- a valid
input.nml
namelist file for DART - a valid
ncommas_vars.nml
namelist file for ncommas - the same one used to create the DART state vector, naturally, - a DART file (typically
filter_restart.xxxx
orfilter_ics.xxxx
) - a ncommas restart file (typically
ncommas_restart.nc
).
Since this program is called repeatedly for every ensemble member, we have found it convenient to link the DART input
file to the default input filename (dart_restart
). The same thing goes true for the ncommas output filename
ncommas_restart.nc
.
This namelist is read from the file input.nml
. Namelists start with an ampersand '&' and terminate with a slash '/'.
Character strings that contain a '/' must be enclosed in quotes to prevent them from prematurely terminating the
namelist.
&model_nml ncommas_restart_filename = 'ncommas_restart.nc'; assimilation_period_days = 1, assimilation_period_seconds = 0, model_perturbation_amplitude = 0.2, output_state_vector = .true., calendar = 'Gregorian', debug = 0 /
&dart_to_ncommas_nml dart_to_ncommas_input_file = 'dart_restart', advance_time_present = .false. /
dart_to_ncommas_nml
and model_nml
are always read from a file called input.nml
. The full description of the
model_nml
namelist is documented in the NCOMMAS model_mod.
Item | Type | Description |
---|---|---|
dart_to_ncommas_input_file | character(len=128) | The name of the DART file containing the model state to insert into the ncommas restart file. |
advance_time_present | logical | If you are converting a DART initial conditions or restart file
this should be .false. ; these files have a single timestamp
describing the valid time of the model state. If .true. TWO
timestamps are expected to be the DART file header. In this
case, a namelist for ncommas (called ncommas_in.DART ) is
created that contains the &time_manager_nml settings
appropriate to advance ncommas to the time requested by DART. |
ncommas_vars_nml
is always read from a file called ncommas_vars.nml
.
Item | Type | Description |
---|---|---|
ncommas_state_variables | character(len=NF90_MAX_NAME) :: dimension(160) | The list of variable names in the NCOMMAS restart file to use to create the DART state vector and their corresponding DART kind. |
&ncommas_vars_nml ncommas_state_variables = 'U', 'QTY_U_WIND_COMPONENT', 'V', 'QTY_V_WIND_COMPONENT', 'W', 'QTY_VERTICAL_VELOCITY', 'TH', 'QTY_POTENTIAL_TEMPERATURE', 'DBZ', 'QTY_RADAR_REFLECTIVITY', 'WZ', 'QTY_VERTICAL_VORTICITY', 'PI', 'QTY_EXNER_FUNCTION', 'QV', 'QTY_VAPOR_MIXING_RATIO', 'QC', 'QTY_CLOUDWATER_MIXING_RATIO', 'QR', 'QTY_RAINWATER_MIXING_RATIO', 'QI', 'QTY_ICE_MIXING_RATIO', 'QS', 'QTY_SNOW_MIXING_RATIO', 'QH', 'QTY_GRAUPEL_MIXING_RATIO' /
assim_model_mod location_mod model_mod null_mpi_utilities_mod obs_kind_mod random_seq_mod time_manager_mod types_mod utilities_mod
- DART initial conditions/restart file; e.g.
filter_ic
- DART namelist file;
input.nml
- ncommas namelist file;
ncommas_vars.nml
- ncommas restart file
ncommas_restart.nc
- ncommas restart file;
ncommas_restart.nc
- ncommas namelist file;
ncommas_in.DART
none